Method of and apparatus for perforating sheet material



G.F. RYAN 2,405,114

METHOD OF AND APPARATUS FOR PERFCRATING S HEET MATERIAL Filed Sept. 2'7, 1944 3 Sheets-Sheet 1 Inventor George EEycm Aug. 13, 1946. G. F. RYAN 2,405,734

I METHOD OF AND APPARATUS FOR PERFORATING- SHEET MATERIAL I Filed Sept. 27, 1944 I v s Sheets-Sheet 2' 5 Hill! George F Eg s Attorney G. F. RYAN Aug. 13, 1946.

METHOD OF AND APPARATUS FOR PERFORATING SHEET MATERIAL Filed Sept. 27, 1944 s Sheets-Sheet,3

[nu enfor Georg FIR an Patented Aug. 13, 1946 UNlTED STATES TENT orric Application September 27, 1944, Serial No. 555,922

This invention relates to the art of perforating sheet material and is herein illustrated in connection with a method of perforating shoe part blanks by the use of fluid under high pressure.

In perforating sheet material. for use in Various industries, and particularly in the shoe manufacturing industry in connection with the formation of shoe part blanks, use is commomy" made of dies provided with a plurality of punches for producing the perforations in the material. It frequently happens that, as in the case of shoe tips or vamps, a large number of perforations are'emplayed for ornamental purposes. This results in the necessity for using a correspondingly large number of punches, which must be accurately shaped and located in the dies in order to produce satisfactory blanks,- with the result that the cost of the dies themselves is high,

It is an object of the present invention to provide a method cfperforating sheet material so that a Considerable portion of the expense heretofore resultin from the use of dies will be elimi. nated. To this end and as illustrated, in its method aspect the invention consists in subjecting a blank of sheet material to the action of a fluid under high pressure, or high velocity, or both, to rupture portions of the blank at predetermined points, thereby to perforate the blank. Preferably, the fluid isdi-rcted against the blank in a plurality of jets formed by placing a perforated plate in juxtaposition to the blank to be operated upon. This method renders unnecessary the use of expensive dies having accurately machined and positioned punches.

In another aspect, the invention provides apparatus for carrying out the method referred to. As illustrated, the apparatus comprises a plurality of plates between which the blank to be operated upon is clamped, the plates having perforations in alinenient with each other, and an explosion chamber, the outlet of which is in communication with the perforations in one of the plates, together with means for supplying an explosive mixture to the chamber and for exploding the mixture, with th result that the" products of combustion passing through the perforations in the plates will rupture the blank forming the desired perforations therein. Preferably and as shown, the perforations in the plates are located to form an ornamental design corresponding to a perforated design to be produced in a blank The perforations in the plates can readily be formed by a drilling operation, which is'inexpensive' compared to the formation of punch tubes, heretofore used in perforating dies. For this reason the 11 Claims. (Cl. 164--93) 2 first cost of the apparatus iscomparatively low, and, furthermore, the cost ofpower'for operating the apparatus is negligible. I

These and other features or the invention are disclosed in the accompanying specification and in the drawings, and are pointed out in the claims.

In the drawings, Fig. 1 is a view in side elevation of apparatus illustrating one embodiment of m invention;

Fig. 2 is a plan view of the apparatus shown in g.

3 is a cross section taken along line III-III of Fig. 1; Q

Fig. 4 is a plan view of a completed blank produced by the apparatus; and

Fig. 5 is a diagram of the electrical connections for the apparatus.

The apparatus is used for operating' upon shoe part blanks, such as a tip [0 illustrated in Fig. 4, to produce an ornamental design comprising a plurality of perforations l2,

The method employed for producing perforations in the blank briefly consists in positioning the blank between two perforated plates l4 and I6, and subjecting the blank to the action of a fluid under pressure in an explosion chamber 18.

The explosion chamber l8 comprises a hollow casting having an outlet port 20, adjacent to which the plates' M and 15 are located. Connected to the chamber is an explosive fluid supply line 22 and within the chamber is located a spark plug 2d for exploding the mixture at the proper time. The plate [4 is arranged tobe secured to the upper outer surface of the chamber l8 by bolts 26, the central portion 28 of the plate being comparativeh' thin and being positioned in alinement with the outlet port 20. The central portion of the plate is provided with perforations 30 corresponding to the perforated design, which it is desired to produce in the blank Ill The plate It, which forms" a backing plate, i provided with perforations 32 corresponding in shape and size to perforations 3-0- in the plate It. Preferably, the

erforations in the two plates are readily produced by clamping the plates together and drilling holes through bothplates in one operation.

The plates are arranged to be interchangeable with other plates having differently arranged perforations, so that a wide variety of perforateddesigns may be produced in blanks. The plate I I6 is secured by bolts 34 to a bolster plate 36, which, in turn, is secured by the same bolts to a cover plate 38 mounted upon a pivot 39 carried by a boss 42 on the top of the chamber l8. This arnut 42. The purpose of this is to prevent separationof the plates at such time as an explosion takes place in the chamber 18.

In orderto provide for the removal of waste gases from the chamber 18, the bolster plate 36 is provided with an expansion chamber 44 .t which is connected a flexible pipe 46, which is preferably connected to a suction pump (not shown). The chamber I8 is provided with an inlet port 48, Fig, 1, upon the inner end of which is seated a ball valve 50, the arrangement being such that during an explosion in the chamber the ball valve will be closed but that, thereafter,

when the chamber is connected to th pipe 46,

the valve will open to permit scavenging of the gases in the chamber and to permit the inflow of air.

Any suitable explosive mixture may be used,

7 such a a, mixture of gasoline and air, acetylene gas, or other fluid. The mixture is introduced through the supply line at 22, which is controlled by a valve 52. This valve is operated by a foot treadle 54 pivoted at 56 .on the casting and operating through a loose link 58 a gear segment 60, which is in mesh with a second gear segment 62 for rotating the valve. The treadle is normally maintained in raised position by a spring 64, which tends to move the segment 60 in a clockwise direction into engagement with a stop 66. Upward movement of the treadle under actionof the spring 64 is cushioned by a springpressed plunger 68 carried by a boss on the side of the chamber 18.

The electrical circuit for effecting ignition of explosive fluid by the spark plug comprises an.

inductance coil 12, a safety switch 14, a treadleoperated switch 16, and a source of current 18.

suitably connected in a circuit by leads 84, 86, 88. 90 and 92. The wiring diagram including these elements is shown in Fig. 5. The purpose of the safety switch 14 is to prevent ignition in the event that the cover plate 38 is not in its lowermost.

position with the backing plate It located in alinement with the outlet port 20. To this end, the plate 38 is provided with a depending lug 9.: carrying a set screw 96 for operating a button 98 controlling the switch 14. The arrangement is such that the circuit through the switch 14 is open until such time as the push button 98 is forced inwardly by reason of the fact that the cover plate 38 is in its lowermost position. The circuit through the 'treadle-operated switch 16 is open when the treadle 54 is in raised position with a'set screw I00 thereon forcing a push button H12 of the switch inwardly. Downward movement of the lever releases the button and closes the circuit through the switch. Thus, when the cover plate 38 is in its lowermost position and the treadle 54 is depressed, the valve 52 will be opened to permit flow of explosive fluid into the chamber 18. Downward movement of the treadle effects closing of the circuit through the switch 16, with the result that the coil 12 is energized. When the treadle is released, the spring 64 causes it to move upwardly, eflecting a, closing of the valve 52 and, at the end of the upward movement ings in the plate.

4 of the treadle, the switch 1-6 is opened, with the result that the residual current in the coil causes a spark across the terminals of the spark plug and effects an explosion of the mixture.

The mixture under high pressure and high velocitypasses through the perforations in the plate 14, ruptures the material of the blank to form perforations therein, and passes out through the perforations in the backing plate It. Suction through the waste pipe 46 withdraws the waste gases, fresh air being admitted through the ball valve 50.

'It is to be noted that, because of the high velocity and pressure of the gases passing through the material of the blank, the openings formed correspond closely in cross section to the open- Furthermore, the ragged edges, which are commonly found in blanks perforated by punch tubes, particularly when such tubes are dull, are eliminated bythe use of the present device.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of perforating sheet material which consists in clamping the material between one of the plates to the action of a fluid moving at high velocity.

3. The method of perforating sheet material which consists in clamping the material between two perforated plates, the perforations of which are in alinement, and subjecting the assembly to the action of a fluid moving at sufficiently high velocity to pass through the perforations, thereby disrupting the material adjacent to the perforations.

4. The method of perforating sheet material which consists in clamping the material between two plates having alined openings, locating the assembly in juxtaposition to an opening in a chamber containing fluid under pressure sufliciently high to cause fluid to disrupt the sheet material adjacent to the perforations.

5. The method of perforating sheet material which consists in clamping the material between two perforated plates in juxtaposition to the mouth of an explosion chamber, supplying an explosive fluid mixture to the chamber, and detonating the mixture, thereby applying pressure to the material adjacent to the perforations sufficiently great to rupture the material.

6. The method of ornamenting shoe part blanks which consists in clamping a blank between two perforated plates in which the perforations are in alinement with each other, placing the assembly in an opening in a fluid pressure chamber, and raising the pressure in the chamber sufficiently to cause the fluid to disrupt the material of the blank adjacent to the perforations..

7. A perforating machine comprising a pressure chamber having an opening therein, a perforated plate located within the opening, means for securing a blank to be operated upon in close relation to the plate, and means for supplying fluid under pressure to the chamber for disrupting the blank adjacent to the perforations in the plate.

8. A perforating machine comprising a pressure chamber having an opening therein, a perforated plate located in juxtaposition to the opening, means for clamping upon the plate a blank to be operated upon, means for supplying an explosive mixture to the chamber, and means for exploding the mixture, thereby to disrupt the blank adjacent to the perforations in the plate.

9. A perforating machine comprising a pressure chamber having an opening therein, a perforated plate located in the opening, a cover pivotally mounted upon the chamber, a second perforated plate carried by the cover and movable into alinement with the first-mentioned plate, means for securing the two plates in fixed position with a blank to be operated upon positioned between them, and means for directing fluid moving at high velocity from the chamber through the plates, thereby to perforate the blank.

10. A perforating machine comprising a pressure chamber having an opening therein, a plate located adjacent to the opening and having perforations therein, an arm pivotally mounted upon the chamber, a second plate carried by the arm and movable into juxtaposition to the first-mentioned plate, said second-mentioned plate having perforations in alinement with the first-mentioned plate when the two plates are close together, a supply line for supplying an explosive mixture to the chamber, means for igniting the mixture including a spark plug, a fluid control valve, manually operated means for controlling the valve, and means for initiating an operation of the spark plug subsequently to operation of the valve in admitting fluid to the chamber.

11. A perforating machine comprising a pressure chamber having an opening therein, a plate located adjacent to the opening and having perforations therein, an arm pivotally mounted upon the chamber, a second plate carried by the arm and movable into juxtaposition to the first-mentioned plate, said second-mentioned plate having perforations in alinement with the first-mentioned plate when the two plates are close together, a supply line for supplying an explosive mixture to the chamber, means for igniting the mixture including a spark plug, a fluid control valve, manually operated means for controlling the valve, means for initiating an operation of the spark plug subsequently to operation of the valve in admitting fluid to the chamber, and electrical connections between the manually operable means and the spark plug for preventing operation of the spark plug when the arm is in raised position.

GEORGE F. RYAN. 

